This invention relates to a connector for connecting, for instance, wire harnesses in a motor vehicle, and more particularly to an improvement of the connector to prevent metal terminals from being inserted into the terminal accommodating chambers of a connector housing upside down, and to prevent the unintentional removal of the metal terminals.
A conventional connector of this type is as shown in FIGS. 9 through 11. In these figures, reference character a designates a connector housing; b, a terminal locking member; and c, a metal terminal. The connector housing a has terminal accommodating chambers a.sub.1, in each of which a first flexible locking piece a.sub.2 is provided for the metal terminal c. As for each terminal accommodating chamber, the terminal locking member b has a pair of second flexible locking pieces b.sub.1.
The terminal locking member b has temporary locking pieces b.sub.2 with temporary locking protrusions b.sub.2', and a final locking piece b.sub.3 with a final locking protrusion b.sub.3'. These protrusions are engaged with the locking portions of locking frames a.sub.3 formed in the connector housing a.
The metal terminal c comprises an electrical contact portion c.sub.1, and a wire connecting portion c.sub.2. The electrical contact portion has a bottom portion c.sub.3, and a pair of stabilizers c.sub.4 extended downwardly from the bottom portion c.sub.3 to regulate the posture of the metal terminal inserted into the terminal accommodating chamber a.sub.1. The terminal locking member b has insertion holes b.sub.6 formed in its main frame b.sub.4. Passage guide protrusions b.sub.6 having smooth guide surfaces b.sub.6', which are for instance arcuate in correspondence to the configuration of the bottom portion c.sub.3, are formed in the insertion holes b.sub.3 of the terminal locking member b. Passage permitting grooves b.sub.7 are formed beside the passage guide protrusions b.sub.6 in correspondence to the stabilizers c.sub.4 of the metal terminals c.
With the temporary locking protrusions b.sub.2' temporarily engaged with the locking portions of the locking frame a.sub.3, the metal terminal c is inserted into the terminal accommodating chamber a.sub.1 through the insertion hole b.sub.5 in the main frame b.sub.4 of the terminal locking member b. In this operation, the bottom portion c.sub.3 abuts against the passage guide protrusions b.sub.6 ; however, it passes over the passage guide protrusions readily because the latter have the smooth guide surfaces b.sub.6', while the stabilizers c.sub.4 are moved along the passage permitting grooves b.sub.7. Thus, the metal terminal can be smoothly inserted into the terminal accommodating chamber a.sub.1.
If the metal terminal is erroneously disposed upside down when inserted, then the stabilizers c.sub.4 are caused to abut against the upper portion of the main frame b.sub.4, thus preventing the metal terminal from being inserted upside down.
The size of the insertion hole b: depends on that of the wire connection portion c.sub.2. Therefore, in the case where the wire connecting portion is increased in dimension, it is necessary to increase the amount of protrusion of the stabilizers c.sub.4.
In the above-described conventional connector, the stabilizers greatly protruded from the metal terminal are utilized to eliminate the difficulty that the metal terminal is inserted upside down. For instance, when the metal terminal is connected to a wire, the stabilizers thus formed may damage the wire by scratching it.
In order to lock the metal terminal into the terminal accommodating chamber of the connector housing, in general a flexible locking arm is provided on the inner wall of the terminal accommodating chamber. That is, when the metal terminal is inserted into the terminal accommodating chamber, the flexible locking arm thus provided is engaged with the metal terminal so as to prevent the difficulty that the metal terminal is unintentionally removed. Recently, a connector has been proposed in the art in which a terminal locking member is provided behind the connector housing which, together with or instead of the flexible locking arm, acts to positively eliminate the difficulty that the metal terminal is unintentionally removed from the connector (cf. Japanese Utility Patent Application (OPI) No. 34083/1990 (the term "OPI" as used herein means an "unexamined published application").
FIG. 12 shows another example of the conventional connector, which comprises a connector housing a", and a terminal locking member b". In FIG. 12, the terminal locking member b" is temporarily engaged with the connector housing a" (the locking mechanisms of the connector housing and the terminal locking members being is not illustrated).
The connector housing a" has a plurality of terminal accommodating chambers c". Each of the terminal accommodating chambers c" has a flexible locking piece e" for locking a metal terminal d" in correspondence to the respective terminal accommodating chamber c", and a terminal retaining piece g" which is in the respective terminal accommodating chamber c".
The connector thus constructed is used as follows: That is, with the terminal locking member b" temporarily engaged with the connector housing a", the metal terminal d" is inserted into the terminal accommodating chamber c" through the insertion hole f". In this operation, as shown in the upper half of FIG. 13, the metal terminal d" is inserted while flexing the terminal retaining piece g" which is in its way, and the flexible locking piece e" is then deflected. When the metal terminal has been fully inserted, the flexible locking piece e" is restored to lock the metal terminal d". Thereafter, the terminal locking member b" is inserted into the connector housing a"; that is, the terminal locking member b" is completely engaged with the connector housing a". As a result, the terminal retaining piece g" also locks the metal terminal d", thus preventing the unintentional removal of the metal terminal d". The connector thus constructed is disadvantageous in the following point. As shown in FIG. 12, a gap m is provided between the terminal locking member b" and the partition wall h" between the upper and lower terminal accommodating chambers c" and c". Therefore, if the metal terminal d" is slightly inclined as shown in the lower half of FIG. 13 When inserted, then the end d".sub.1 will strike against the rear end h".sub.1 of the partition wall h", thus obstructing the smooth insertion of the metal terminal.